Interactive figures

for 'TSH and FT4 reference interval recommendations: optimization of current methods'

 

Interactive heatmaps depict the F-scores (diagnostic performance measure of sensitivity and positive predictive value) for various modifications of the non-pregnancy TSH upper limit and the non-pregnancy FT4 lower limit. 

Hoovering over the figures reveals other diagnostic performance measures for that particular combination of TSH and FT4 reference limit modification. 

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Performance measures used:

   Sensitivity (true positive rate, true positives among all with a positive test result)

   PPV=Positive Predictive Value (true positives among all with a positive test result)

   CI= Confidence interval

   PI=Prediction interval

   I2= I2 statistic (proportion of total variability in effect sizes due to true heterogeneity rather than 

         sampling error) 

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Methods used to simulate the current standard 'trimester specific reference intervals':

   1) Relative subtraction from upper limit of TSH varying from -5% to -50% in steps of 5% with subtraction or additions to the lower limit of FT4 varying from -20% to +20% in steps of 5% (relative subtraction approach),

   2) Subtraction from the upper limit of TSH varying from -0.1 to -1.0 mU/L with subtraction or additions to the lower limit of FT4 varying from -5 to +5 pmol/L (-0.39 to +0.39 ng/dL; absolute subtraction approach) and

   3) Using nonpregnancy reference limits with a fixed upper limit for TSH, varying from 3.0 to 4.5 mU/L, and a fixed lower limit for FT4, varying from 5 to 15 pmol/L (0.39-1.17 ng/dL; fixed limit approach).

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Please see the original manuscript for a detailed description of the methodology (link will be added after publication).